Summer Cover Crop
I have a garden plot about 30x50 that I have to let go fallow this summer. I would like to plant a summer cover crop as a green manure. I am considering buckwheat. Does anyone have any better suggestions? I don't have a tractor so I can't plant sudan-soughum grass because I have no way to cut it. I live in zone 5. I need something to suppress weeds.
Thank you for your advice.
I planted buckwheat in my garden beds last summer and will do the same any day now. I did a lot of research before deciding on buckwheat and cow peas as my green manure. Crown vetch is another recommended cover crop, but from what I've seen it can become invasive if not cut down in time.
I have four L-shaped beds, roughly 54 square feet each plus two 32 square foot beds. I put buckwheat in all of them over the summer, cutting it down by hand after it had flowered but before it set seed (it's important to cut down whatever cover crop you use before seed set, else it will take over). A day or two later I hand dug the buckwheat into the beds. Still experienced the occasional resprouting, but so few that it wasn't a problem to pull the shoots by hand. Used cowpeas following basically the same routine, but here in florida I use them as a winter cover crop. I planted the buckwheat and peas quite thickly, had great germination (and the bees loved the buckwheat flowers). Lovely being in the garden when the buckwheat is in bloom, the air is filled with its fragrance.
Both grew really well for me, and weeds weren't a problem. But then I'm out there just about every day obsessively pulling weed sprouts - where I live you've got to stay on top of 'em else they're likely to take over before you know it.
In a northern climate such as zone 5 buckwheat is one of the best options for producing dense shade quickly in the summer. It will choke out weeds pretty fast. I do not think any legumes will establish high shade density fast enough. The downside is that buckwheat will have to be cut down in perhaps eight weeks to prevent seed. The hollow stems rot quickly with even rough chopping.
Cereal rye can be planted in early August for green manure and will quickly become dense enough to suppress weed growth. Cereal rye can be turned under in the fall or will hold to provide cover until spring. If you keep it for winter cover, mow and till under before it gets over four inches tall after coming out of dormancy. Annual (not perennial) rye grass becomes established pretty fast but not as fast as cereal rye if you want a temporary cover crop for late summer but will not suppress weeds as well.
I second Eldon's recommendation. Buckwheat sounds ideal for your situation. His caveats are right on.
I published an extension guide specifically about using buckwheat cover crops in Zone 5. You can find it at
There are some helpful hints in the last few pages that can help you avoid bad surprises and let you get the most out of your planting.
I've had success establishing Medium Red Clover in buckwheat when there was a lot of rainfall. Just broadcast the seed over soil after planting the buckwheat. It's the only legume that is shade tolerant enough to establish under buckwheat. It will grow a lot after you cut the buckwheat and will last through the winter.